Impact test behavior of aluminum alloys welded joints: Experimental and numerical analysis

The Charpy impact test behavior of base metal, weld metal, and heat-affected zone for 6061-T6 and 7075-T651 aluminum alloy welds was analyzed. Force versus time curves of welded joints were obtained by means of an instrumented Charpy pendulum. An explicit finite element model was implemented to evaluate the performance of the Cowper–Symonds constitutive model. Parameters were obtained through a strain-rate-sensitivity analysis of base metals at high strain rates. Experimental results were compared with those computed by finite element method (FEM) by assuming the same physical and geometrical conditions of the dynamic-experimental tests. ANSYS-LS DYNA was used to achieve the FEM simulations. The comparison between experimental and FEM results in terms of force versus time data was evaluated. Higher accuracies were observed in Al 7075-T651 alloy (roughly 98%). The 6061-T6 alloy has shown an approximation of about 90%. Discrepancies are explained in terms of the effective plastic strain at fracture.